/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2011 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.springframework.asm;

/**
 * A reference to a field or a method.
 *
 * @author Remi Forax
 * @author Eric Bruneton
 */
public final class Handle {

	/**
	 * The kind of field or method designated by this Handle. Should be
	 * {@link Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC},
	 * {@link Opcodes#H_PUTFIELD}, {@link Opcodes#H_PUTSTATIC},
	 * {@link Opcodes#H_INVOKEVIRTUAL}, {@link Opcodes#H_INVOKESTATIC},
	 * {@link Opcodes#H_INVOKESPECIAL}, {@link Opcodes#H_NEWINVOKESPECIAL} or
	 * {@link Opcodes#H_INVOKEINTERFACE}.
	 */
	final int tag;

	/**
	 * The internal name of the class that owns the field or method designated
	 * by this handle.
	 */
	final String owner;

	/**
	 * The name of the field or method designated by this handle.
	 */
	final String name;

	/**
	 * The descriptor of the field or method designated by this handle.
	 */
	final String desc;


	/**
	 * Indicate if the owner is an interface or not.
	 */
	final boolean itf;

	/**
	 * Constructs a new field or method handle.
	 *
	 * @param tag   the kind of field or method designated by this Handle. Must be
	 *              {@link Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC},
	 *              {@link Opcodes#H_PUTFIELD}, {@link Opcodes#H_PUTSTATIC},
	 *              {@link Opcodes#H_INVOKEVIRTUAL},
	 *              {@link Opcodes#H_INVOKESTATIC},
	 *              {@link Opcodes#H_INVOKESPECIAL},
	 *              {@link Opcodes#H_NEWINVOKESPECIAL} or
	 *              {@link Opcodes#H_INVOKEINTERFACE}.
	 * @param owner the internal name of the class that owns the field or method
	 *              designated by this handle.
	 * @param name  the name of the field or method designated by this handle.
	 * @param desc  the descriptor of the field or method designated by this
	 *              handle.
	 * @deprecated this constructor has been superseded
	 * by {@link #Handle(int, String, String, String, boolean)}.
	 */
	@Deprecated
	public Handle(int tag, String owner, String name, String desc) {
		this(tag, owner, name, desc, tag == Opcodes.H_INVOKEINTERFACE);
	}

	/**
	 * Constructs a new field or method handle.
	 *
	 * @param tag   the kind of field or method designated by this Handle. Must be
	 *              {@link Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC},
	 *              {@link Opcodes#H_PUTFIELD}, {@link Opcodes#H_PUTSTATIC},
	 *              {@link Opcodes#H_INVOKEVIRTUAL},
	 *              {@link Opcodes#H_INVOKESTATIC},
	 *              {@link Opcodes#H_INVOKESPECIAL},
	 *              {@link Opcodes#H_NEWINVOKESPECIAL} or
	 *              {@link Opcodes#H_INVOKEINTERFACE}.
	 * @param owner the internal name of the class that owns the field or method
	 *              designated by this handle.
	 * @param name  the name of the field or method designated by this handle.
	 * @param desc  the descriptor of the field or method designated by this
	 *              handle.
	 * @param itf   true if the owner is an interface.
	 */
	public Handle(int tag, String owner, String name, String desc, boolean itf) {
		this.tag = tag;
		this.owner = owner;
		this.name = name;
		this.desc = desc;
		this.itf = itf;
	}

	/**
	 * Returns the kind of field or method designated by this handle.
	 *
	 * @return {@link Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC},
	 * {@link Opcodes#H_PUTFIELD}, {@link Opcodes#H_PUTSTATIC},
	 * {@link Opcodes#H_INVOKEVIRTUAL}, {@link Opcodes#H_INVOKESTATIC},
	 * {@link Opcodes#H_INVOKESPECIAL},
	 * {@link Opcodes#H_NEWINVOKESPECIAL} or
	 * {@link Opcodes#H_INVOKEINTERFACE}.
	 */
	public int getTag() {
		return tag;
	}

	/**
	 * Returns the internal name of the class that owns the field or method
	 * designated by this handle.
	 *
	 * @return the internal name of the class that owns the field or method
	 * designated by this handle.
	 */
	public String getOwner() {
		return owner;
	}

	/**
	 * Returns the name of the field or method designated by this handle.
	 *
	 * @return the name of the field or method designated by this handle.
	 */
	public String getName() {
		return name;
	}

	/**
	 * Returns the descriptor of the field or method designated by this handle.
	 *
	 * @return the descriptor of the field or method designated by this handle.
	 */
	public String getDesc() {
		return desc;
	}

	/**
	 * Returns true if the owner of the field or method designated
	 * by this handle is an interface.
	 *
	 * @return true if the owner of the field or method designated
	 * by this handle is an interface.
	 */
	public boolean isInterface() {
		return itf;
	}

	@Override
	public boolean equals(Object obj) {
		if (obj == this) {
			return true;
		}
		if (!(obj instanceof Handle)) {
			return false;
		}
		Handle h = (Handle) obj;
		return tag == h.tag && itf == h.itf && owner.equals(h.owner)
				&& name.equals(h.name) && desc.equals(h.desc);
	}

	@Override
	public int hashCode() {
		return tag + (itf ? 64 : 0) + owner.hashCode() * name.hashCode() * desc.hashCode();
	}

	/**
	 * Returns the textual representation of this handle. The textual
	 * representation is:
	 *
	 * <pre>
	 * for a reference to a class:
	 * owner '.' name desc ' ' '(' tag ')'
	 * for a reference to an interface:
	 * owner '.' name desc ' ' '(' tag ' ' itf ')'
	 * </pre>
	 * <p>
	 * . As this format is unambiguous, it can be parsed if necessary.
	 */
	@Override
	public String toString() {
		return owner + '.' + name + desc + " (" + tag + (itf ? " itf" : "") + ')';
	}
}
